에어컨 냉각 팬용 브러쉬레스 DC 전동기의 역기전력 분석에 대한 연구

조정현,김지현,정정원,황흥식,이치우 경성대학교 공학기술연구소 2012 공학기술연구지 Vol.18 No.-

Compared to conventional dc motors having the combination of commutators and brushes, a brushless DC (BLDC) motor is one of the highly efficient motors due to its electrical commutation without a brush, and this feature allows the BLDC otor to be more suitable for an application requiring no maintenance due to mechanical wear between a commutator and a brush. Also, the BLDC motor has a few benefits over both a dc motor and an induction motor such as high dynamic response, high efficiency, logn life span, and low noise in wide speed-torque region. This paper investigates the variation of voltage induced in phase windings in a BLDC motor in several cases with respect to stack length, steel grade, and coil material. This study is numerically conducted and it is verified from the theoritical point of view by comparing the result of simulation with that of experimental measurement.

Production and Characterization of Enzymes Involved in Chitin Catabolic Cascade from a Bacterial Strain Isolated from Soil

( Ji Hyun Lee ),( Jeong In Lee ),( So Yeon Park ),( Yoo Kyeong Jang ),( You Bin Lim ),( Hye Yoon Lee ),( Young Min Jung ),( Hae Chang Lee ),( Jong Hwa Lee ),( Shaheen Amna ),( Jae Kweon Park ) 한국키틴키토산학회 2019 한국키틴키토산학회지 Vol.24 No.1

The present study was aimed to isolate the bacteria producing chitinolytic enzymes including chitin deacetylase (CDA) from soil origin. About 24 bacteria were screened for their chitinolytic enzymes producing ability on the basis of colloidal chitin. Amongst one of the most potent isolates designated to JI-02 was further selected as the most prominent chitinolytic and CDAlike enzyme (CDA-X) producer based on the ability of deacetylation of an artificial substrate pNP-acetamilide. The maximum production of CDA-X in crude enzyme from JI-02 was observed in the presence of 1% colloidal chitin at 37°C and pH 6.4 after 120 h of incubation. Potent enzyme activity of CDA-X was determined toward pNP-acetamilide, demonstrating that optimal pH, temperature and ionic strength of the CDA-X were assessed to be 7.0, 52°C and 125 mM, respectively. Unexpectedly, Nacetylglucosamine (GlcNAc) was not fully converted by the action of CDA-X to glucosamine (GlcN) under the established conditions. Further study on enzyme activity toward chitin-oligosaccharides consisting of multi-N-acetylglucosamine (GlcNAc)n, n=2-5 may be necessary to elucidate the mode of action which requires the minimum size of (GlcNAc)n. However, our data suggest that CDA-X can convert chitin to chitosan with the maximum yield of approximately 0.08g/L during the fermentation of the strain in the presence of chitin. Furthermore, we found that crude enzyme showed the significant chitosanolytic activity. Taken together, our data suggest that the strain JI-02 may be a potential candidate as a particular strain for better understating of chitin catabolic pathway.

학습공동체 프로그램 질과 인지적 성취 간에 집단응집성, 협력적 자기조절의 매개효과

유지현(Yu, Ji-Hyun),이숙정(Lee, Sook-Jeong),권진백(Kwon, Jin-Baek) 한국경영교육학회 2021 경영교육연구 Vol.36 No.1

[연구목적] 본 연구는 비교과 프로그램 형태의 학습공동체 운영 개선을 위해 학습공동체 프로그램 질 척도를 개발하고, 학습공동체 프로그램의 질과 인지적 성취의 관계에 집단응집성 및 협력적 자기조절의 매개효과를 검증하고자 하였다. [연구방법] 학습공동체 관련 선행연구들과 S대학에서 운영한 학습공동체 만족도 조사 및 성찰일지를 분석하여 학습공동체 프로그램 질 척도 예비문항을 개발하고, 학습공동체에 참여한 대학생 299명을 대상으로 설문조사를 실시, 분석하였다. 또한 집단응집성 및 협력적 자기조절의 매개효과를 확인하기 위해 대학생 322명을 대상으로 설문조사를 실시, 분석하였다. [연구결과] 학습공동체 프로그램 질 척도는 11개 문항, 단일요인으로 개발하였으며, 탐색적 및 확인적 요인분석, 신뢰도 계수 산출을 통해 안정적인 척도임을 확인하였다. 또한 학습공동체 프로그램 질과 인지적 성취 간에 집단응집성 및 협력적 자기조절의 매개효과가 통계적으로 유의한 것으로 나타났다. [연구의 시사점] 본 연구에서 개발한 학습공동체 프로그램 질 척도를 활용함으로써 프로그램의 내실화 및 질 관리 방안을 수립할 수 있다. 또한 집단응집성 및 협력적 자기조절의 중요성을 규명함으로써 학습공동체 프로그램 운영의 시사점을 제공하였다. [Purpose] The purpose of this study was to develop the learning community program quality scale for improving a learning community program and to verify the mediating effect of group cohesion and collaborative self-regulation on the relationship between program quality and cognitive achievement. [Methodology] A questionnaire survey of 299 university students was conducted to develop the learning community program quality scale. To confirm the mediating effect of group cohesion and collaborative self-regulation, a questionnaire survey was conducted on 322 college students. [Findings] The learning community program quality scale was developed with 11 items and a single factor, and it was confirmed to be a stable scale. And, it was found that the mediating effect of group cohesion and collaborative self-regulation between the learning community program quality and cognitive achievement was significant. [Implications] Implications for the management of learning community program to promote group cohesion and collaborative self-regulation were provided.

CFA Analysis에 의한 구강세균의 동정

정현자,조명숙,지원대 한국위생과학회 2002 한국위생과학회지 Vol.8 No.2

충치환자의 병변으로부터 세균을 분리하여 동정하였다. 10종의 세균 CHJ-1, CHJ-2, CHJ-3, CHJ-4, CHJ-6, CHJ-7, CHJ-8, CHJ-9, CHJ-10, CHJ-12이 순수분리되었고, 미국 Analytical Services, Inc.의 Cellular fatty acid analysis에 의한 identification system으로 동정한 결과, CHJ-1, CHJ-2, CHJ-3과 CHJ-12는 각각 Bradyrhizobium japonicum, Arthrobacter pascens, Staphylococcus epidermidis 및 Arthrobacter pascens와 유의성이 0.5이상으로 나타났다. Oral bacteria were isolated and identified. Ten Kinds of bacteria, such as CHJ-1, CHJ-2, CHJ-3, CHJ-4, CHJ-6, CHJ-7, CHJ-8, CHJ-9, CHJ-10, CHJ-12, were isolated from oral cavity of dental patients. These bacteria were identified by cellular fatty acid(CFA) analysis system at Analytical Services Inc. in USA. Similarity index values of bacteria, CHJ-1, CHJ-2, CHJ-3, CHJ-5, CHJ-11 and CHJ-12 were above 0.5 to Bradyrhizobium japonicum, Arthrobacter pascens, Staphylococcus epidermidis and Arthrobacter pascens, respectively.

신속한 간흡충증 진단과 혈청 및 혈구 변화양상 분석

박지현,최혜정,정석률 남서울대학교 2010 남서울대학교 논문집 Vol.16 No.2

Diagnosis of Clonorchis sinensis requires specific proteins as antigens and it has been developed by using a rapid detection kit which identify circulating antibodies. In this study during Namseoul University Health/Medicine Care Service conducted in October 2010, with the residents in Wondeok-eup Samcheok Kangwon-do, the rapid diagnosis of C. sinensis infections was performed and patients' blood sera were analyzed. From 12 patients' sera of total 83, antibodies to C. sinensis were detected. According to the patients' sera analysis, about 73% of Total bilirubin, 40% of Cholesterol and 40% of Creatinine were abnormally exhibited. In the C. sinensis-positive sera detected by a rapid diagnostic kit, about 92% of Total bilirubin, 33% of Cholesterol and 50% of Creatinine were abnormally exhibited. According to analysis of blood cells, there was no abnormal result except for Hematocrit. In particular, high Eosinophil which means high incidence of C. sinensis infection was not observed. Taken together, it implied that the positive diagnosis of clonorchiasis would be previous infections of C. sinensis and its patients recovered from clonorchiasis have still antibodies in their sera. In addition, it also suggested that C. sinensis-positivity by the rapid diagnostic kit be not consistent with the present infections of C. sinensis. Key Words : Clonorchis sinensis, Rapid diagnostic kit, Serum, Blood cell, Antibody

地域社會를 위한 環境費用의 公示方法에 관한 硏究

玄智植,鄭永寬 公州大學校 地域開發硏究所 1994 地域開發硏究論叢 Vol.2 No.1

석면함유 슬레이트 지붕 물받이 퇴적물 중 석면 섬유 함유율

임지현,한솔민,김현석,신유민,박시은,허정윤,김민영,장봉기 순천향대학교 기초과학연구소 2022 순천향자연과학연구 논문집 Vol.28 No.1,2

This study attempted to determine the degree of asbestos release from the aging slate roof by comparing the asbestos content in the slate roof rain gutter with a colored steel plate (tin plate) over the slate roof. Four slate roof houses located in Haengmok-ri, Asan-si, Chungcheongnam-do, and one house constructed with a colored steel plate on the slate roof were selected to collect the sediment of the roof rain gutter. The asbestos fiber content was calculated by a point counting method using a polarization microscope after pretreatment with conversion treatment and hydrochloric acid treatment. The average asbestos content of the four slate roof rain gutter were 1.89%. However, asbestos was not detected in the Slate covering roof rain gutter, which were constructed on the slate roof. Asbestos fiber content was the highest at 2.89% in the slate roof rain gutter installed in 1976, followed by 2.44% in 1953. From the above results, it is necessary to minimize secondary damage as asbestos fibers released from slate roof houses to the surrounding atmosphere or leaked from slate roofs as rainwater may cause soil pollution and seriously affect residents' health. Although covering with colored steel plates (tin plates) has been shown to prevent the leakage of asbestos fibers to some extent, it is believed that a policy alternative to remove the slate roof as soon as possible is needed to solve the fundamental problem.

노인과 대학생의 낙상 위험 분석

정다현,김예희,김지은,이예영,강현주 순천향대학교 기초과학연구소 2021 순천향자연과학연구 논문집 Vol.27 No.1.2

The purpose of this study was to analyze risk of falls between elderly people and college students. The subjects of this study were 25 people aged 70 years or older and 17 college students located in Asan. We measured sensory, integrated balance, nervous, musculoskeletal system and HQR by FRA system (Inbody, Korea). The results of measurement showed significant differences in sensory system (p<.01), integrated balance (p<.001), nervous system (p<.001), and musculoskeletal system (p<.001) between groups. These results suggest that aging makes difference of function of these systems. In our view, counterplans need to be implemented, including exercise intervention to prevent decreases of fall risk,

혈액투석 환자에게서 발생한 재생불량성 빈혈 1예

정지용,윤나라,강대웅,오종찬,장재현,선길홍,박경희,정종훈,김현리 朝鮮大學校 附設 醫學硏究所 2005 The Medical Journal of Chosun University Vol.30 No.1

Aplastic anemia is a disease characterized by pancytopenia in the peripheral blood and hypocellular bone marrow with the fatty infiltration. The causes of the acquired aplastic anemia were usually related to drugs and immune-related diseases. A 34-years old man was admitted due to general weakness. He has been going hemodialysis for 2 years because of end stage renal disease (ESRD) due to chronic glomerulonephritis. At admission, laboratory tests showed hemoglobin 6.2 g/dL, hematocrit 18.0 %, WBC 5,710mm (neutrophil 71.8%, lymphocyte 19.1%, monocyte 5.9%), reticulocyte 1.9%, platelet 93,000/mm, Fe 12.8 ug/dL, TIBC 204 ug/dL, ferritin 941.47 ng /ml, haptoglobin 0.72 g/L, vitamin B12 508.17 pmol/L, folate 24 ng/mL, total protein 6.54 g/dL, albumin 3.76 g/dL, Alk. pohsphatase 79 IU/L, AST 30.0 IU/L, ALT 39.7 IU/L, total bilirubin 0.57 mg/dl, BUN 79.4 mg/dl and creatinine 10.18 mg/dl. Peripheral blood smear showed the normocytic normochromic anemia with anisocytosis. Anemia was diagnosed but it was irresponsive to the recombinant human erythropoietin (EPO) and blood transfusion. In the bone marrow aspiration smear were there the hypoplastic myeloid and erythroid precursors. The bone marrow biopsy section showed the hypoplasia of all components (10-20%) and the fatty infiltration. We have experienced one case of the idiopathic aplastic anemia in a patient going through hemodialysis and we just report it with documentary records. 저자들은 혈액 투석 중인 환자에서 약물, 면역계 이상등의 원인을 발견할 수 없었음에도 재생 불량성 빈혈이 발생한 1예를 경험하여 문헌 고찰과 함께 보고하는 바이다.

5종의 치주질환균에 대한 프로폴리스의 항균효과

이은지,김소민,박소민,박복리,홍성익,김현정 순천향대학교 기초과학연구소 2022 순천향자연과학연구 논문집 Vol.28 No.1,2

Since the oral cavity is directly connected to the outside, it is an important site for microbial invasion, and since it is an environment that is nutritionally and physiologically easy to multiply bacteria, many bacteria always form bacteriological flora in the oral cavity. And propolis is a natural treatment used in many health food stores in various forms for local treatment. This study analyzes the changes in the activity of five oral microorganisms before and after consumption of propolis for various age groups to find out how propolis, which shows the efficacy of anti-inflammatory, antibacterial, and immune sensitization, affects oral microorganisms. Five types of bacteria possessed by periodontal disease patients were specified and digitized targeting the public person, and then before and after propolis intake was compared, and the levels of periodontal disease bacteria in the intake group and the non-consumption group were compared. As a result of comparing the patterns before ingestion (0 week) and after ingestion (3 week) in the oral bacteria analysis, it was confirmed that the bacteria decreased overall except for the five populations in the propolis intake group. In contrast, in the comparative group that did not intake propolis, the bacteria of five periodontal disease increased except for the four populations. What can be seen from this result is that propolis is effective in reducing bacteria in five types of periodontal disease. In order to use propolis as a food for preventing periodontal disease and to get a better effect, further research is needed to find out the mechanism of antibacterial action in propolis compounds.